The present invention relates to a portable telephone terminal and a method of customizing the portable telephone terminal, in particular to a portable telephone terminal capable of customizing functions for services of terminals and networks required by a plurality of communication service operators.
Conventionally, a plurality of portable telephone services have been provided by various communication service operators. Recently, each communication service operator has become to provide an original service in order that the original service may be distinguished from portable telephone services provided by the other communication service operators.
Under the circumstances, in manufacturing portable telephone terminals, specifications of portable telephone terminals are determined to have functions required for the original services per each communication service operator, respectively. Accordingly, such portable telephone terminals are adjusted to be sold as special purpose portable telephone terminals, respectively, for portable telephone services provided by each of the communication service operators.
However, it is necessary for a manufacturer of the portable telephone terminals to produce, per each communication service operator, products of the portable telephone terminals having functions required for the services of terminals and networks required by each of the communication service operators. As a result, kinds of the products of the portable telephone terminals are inevitably increased. Further, a cost required for development and production of the portable telephone terminals becomes high.
Furthermore, even if wireless access systems for the portable telephone services provided by each of the communication service operators are, for example, the same as each other, one communication service operator sometimes provide a service in accordance with a standard A while another communication service operator sometimes provide a service in accordance with a standard B. Thus, the services of terminals and networks provided by each of the communication service operators are themselves different from each other.
In order to solve this problem, it is necessary to develop an application software having functions capable of corresponding to both the services A and B. It is then necessary to apply the application software to a portable telephone terminal so that the portable telephone terminal may comply with both of the one and the another communication service operators. Nevertheless, it is impossible to judge how to change and drive the function to correspond to either the service A or the service B. It is therefore difficult to actually enjoy either the service A and the service B.
Moreover, requirements for operability of the portable telephone terminals sometimes differ from each other per each communication service operator. Consequently, it is necessary to develop portable telephone terminals also regarding the operability thereof per each communication service operator. This causes problems similar to those mentioned above. Namely, kinds of the products of the portable telephone terminals are inevitably increased. In addition, a cost required for development and production of the portable telephone terminals becomes high.